Acute hormonal response to cigarette smoking

Preliminary smoking studies using non-smokers were unsatisfactory because the subjects became obviously "ill" with nausea, pallor, sweating, etc. The rise in adrenocorticotropic hormone and growth hormone in these individuals could not be attributed to a cigarette effect as opposed to a nonspecific stress. A small number of female smokers seemed less consistent in their responses than did male subjects. The final study employing male, habitual smokers showed the following results: (1) A sharp rise in circulating cortisol occurred after two cigarettes which was maintained through the 2nd hour and fell slowly after the smoking period. (2) Circulating growth hormones also began to rise after two cigarettes, peaked at 1 hour, and then fell back to control levels while smoking continued. (3) Urinary catecholamines tended to be higher on smoking days than on nonsmoking days, but results were variable and of questionable significance. (4) Luteinizing hormone, follicle stimulating hormone, testosterone, and thyroid-stimulating hormone did not show any significant variations with smoking as compared to non-smoking.

The kinetics of ethanol absorption and elimination in twins and supplementary repetitive experiments in singleton subjects

The influence of genetic and environmental factors on the metabolism of a single oral dose of ethanol 1.2 ml per kg body weight was analysed in 19 identical and 21 fraternal healthy, adult, un-selected male twin pairs. The heritability values of the rates of absorption, degradation and elimination of ethanol were 0.57, 0.41 and 0.46 respectively. Environmental factors, such as daily alcohol intake and smoking, increased the rate of elimination of blood alcohol. Intrasubject variation in ethanol metabolism was studied by repeated tests in 11 male volunteers at intervals of at least 2 months, under the same conditions as in the twins; the coefficients of variation for parameters of metabolism was about 8%. The results demonstrate both genetic control of ethanol absorption, degradation and elimination and the appreciable influence of environmental factors. The almost total genetic control of ethanol metabolism postulated by Vesell et al. (1971) could not be confirmed.

Uptake and metabolism of nicotine by the isolated perfused rabbit lung

In order to investigate the possibility of pulmonary first-pass metabolism of nicotine inhaled in tobacco smoke, the absorption and disposition of 14C-nicotine were studied in an isolated perfused rabbit lung preparation after nicotine administration directly into the perfusing blood and tobacco smoke administration via in the inspired tracheal air. After administration into the perfusing medium, the rate of nicotine metabolism was first-order and dose-independent at the two doses studies (0.1 and 1.0 mg) but lung metabolic clearance was quite low (3 ml/min) relative to whole body clearance (140 ml/min) measured by administering 14C-nicotine to intact rabbits. Accumulation of nicotine by lung was not extensive (13-23% of the dose administered). After administration of tobacco smoke from 14C-nicotine-spiked cigarettes, absorption of nicotine was rapid but the rate of metabolism was markedly reduced compared to the studies in which drug was administered in the perfusing medium. This reduction in the rate of metabolism was apparently caused by some component of tobacco smoke but was shown to be unrelated to the level of carbon monoxide in the perfusate. The slow clearance of nicotine by rabbit lung (which is further reduced after smoke administration) compared to a high pulmonary blood flow rate makes unlikely the possibility of significant first-pass lung metabolism in smokers.

Inhalation experiments with 14C-labelled cigarette smoke. III. Body size dependent distribution of particulate matter in small rodents during cigarette smoke inhalation

Syrian golden and European hamsters were exposed to 14C-labelled cigarette smoke. The deposition of the 14C activity in the respiratory and digestive tracts was determined immediately after the exposure. From the results obtained it can be seen that the distribution of particulate matter between the upper and lower respiratory tract, as well as, between the respiratory and digestive tracts is related to the body weight of the experimental animals.